Laser Polishing of SLE-Surfaces - Fraunhofer ILT · with SLE and LP (fused silica). 2 Chess...
1
In comparison to conventional polishing methods, laser polishing achieves a favorable small micro roughness (rms < 1 nm, spatial wavelength λ < 100 µm). Laser polishing can be adapted to a variety of surface shapes and glass materials (Fused silica, BK7, ULE…) with high processing rates of 1 - 10 cm²/s. Combination of SLE and Laser Polishing With the combination of SLE and laser polishing, complex surface geometries with polished surfaces can be manufac- tured. Due to the thermal process of laser polishing, even the roughness of inner surfaces can be reduced. Hence, with SLE generated micro channels can be post processed e.g. for visual observations of microfluidic processes. sTypical applications of the fabricated glass parts are e.g. microfluidics, microoptics, prototypes, parts for sensors. Contact Christian Weingarten Telephone +49 241 8906-282 [email protected] Dr. Edgar Willenborg Telephone +49 241 8906-213 [email protected] Selective Laser Etching (SLE) SLE is a laser based process to manufacture complex glass parts even with inner geometries e. g. microchannels. By focusing ultrashort laser pulses (300 - 3000 fs) into fused silica the material’s solubility in e. g. KOH is increased by a factor of 1000. A subsequent etching step removes the illuminated material and hence enables the precise (< 10 µm) manufac- turing of three-dimensional cavities in and on glass substrates. But, as a result of the structuring and the etching process the roughness of the fabricated surfaces is too high (approx. 0.2 µm rms) for many applications. Hence, for smooth surfaces an additional process step is necessary. Laser Polishing Polishing glass materials with CO 2 laser radiation is based on the absorption of the laser radiation in a thin surface layer of the work piece. Due to the absorption the surface temperature can be increased above softening temperature. As a result, the viscosity of the material is reduced so that the roughness flows and the surface is smoothened due to surface tension. 1 Aspheres manufactured with SLE and LP (fused silica). 2 Chess figures. 3 Microfluidic (right: SLE-surface, left: laser polished). LASER POLISHING OF SLE-SURFACES Subject to alterations in specifications and other technical information. 07/2017 Fraunhofer Institute for Laser Technology ILT, www.ilt.fraunhofer.de DQS certified by DIN EN ISO 9001, Reg.-No.: DE-69572-01 2 1 3
Transcript of Laser Polishing of SLE-Surfaces - Fraunhofer ILT · with SLE and LP (fused silica). 2 Chess...
In comparison to conventional polishing methods, laser
polishing achieves a favorable small micro roughness
(rms < 1 nm, spatial wavelength λ < 100 µm). Laser polishing
can be adapted to a variety of surface shapes and glass
materials (Fused silica, BK7, ULE…) with high processing
rates of 1 - 10 cm²/s.
Combination of SLE and Laser Polishing
With the combination of SLE and laser polishing, complex
surface geometries with polished surfaces can be manufac-
tured. Due to the thermal process of laser polishing, even the
roughness of inner surfaces can be reduced. Hence, with SLE
generated micro channels can be post processed e.g. for visual
observations of microfluidic processes. sTypical applications of
the fabricated glass parts are e.g. microfluidics, microoptics,
prototypes, parts for sensors.
Contact
Christian Weingarten
Telephone +49 241 8906-282
Dr. Edgar Willenborg
Telephone +49 241 8906-213
Selective Laser Etching (SLE)
SLE is a laser based process to manufacture complex glass
parts even with inner geometries e. g. microchannels. By
focusing ultrashort laser pulses (300 - 3000 fs) into fused silica
the material’s solubility in e. g. KOH is increased by a factor
of 1000. A subsequent etching step removes the illuminated
material and hence enables the precise (< 10 µm) manufac-
turing of three-dimensional cavities in and on glass substrates.
But, as a result of the structuring and the etching process the
roughness of the fabricated surfaces is too high (approx. 0.2 µm
rms) for many applications. Hence, for smooth surfaces an
additional process step is necessary.
Laser Polishing
Polishing glass materials with CO2 laser radiation is based on
the absorption of the laser radiation in a thin surface layer of
the work piece. Due to the absorption the surface temperature
can be increased above softening temperature. As a result, the
viscosity of the material is reduced so that the roughness flows
and the surface is smoothened due to surface tension.
1 Aspheres manufactured
with SLE and LP (fused silica).
2 Chess figures.
3 Microfluidic (right: SLE-surface,
left: laser polished).
LASER POLISHING OF SLE-SURFACES
Sub
ject
to
alt
erat
ion
s in
sp
ecifi
cati
on
s an
d o
ther
tec
hn
ical
info
rmat
ion
. 07/
2017
Fraunhofer Institute for Laser Technology ILT, www.ilt.fraunhofer.de
DQS certified by DIN EN ISO 9001, Reg.-No.: DE-69572-01
21 3
